Glass panel

Abstract

An object is to solve a strength problem around a suction hole on the gap side due to internal stress caused by a suction hole sealing metal material and depressurization, and provide a glass panel having enhanced safety. One glass plate 1 A of a pair of glass plates 1 A, 1 B has a suction hole 4 penetrating the glass plate 1 A in the front-back direction thereof, air in a gap V is sucked so as to depressurize the gap V, and the suction hole 4 is sealed by a suction hole sealing metal material 15 . The suction hole sealing metal material 15 is solidified on the suction hole 4 so as to keep an airtight state, and is formed concentrically with the suction hole 4 in plan view, and the following Expression (1) is satisfied: Dw <=( Fc −0.0361 Pd 2 /Tg 2.2 )/{(−0.0157 Tg +0.1945)* Dg}   (1) where Fc is long-term permissible stress at a glass edge, Tg is a glass plate thickness (mm), Dw is a protruding portion diameter (mm) of the suction hole sealing metal material, Dg is a protruding portion thickness (mm) of the suction hole sealing metal material, and Pd is a spacer pitch (mm).

The invention claimed is: 
     
       1. A glass panel comprising:
 a pair of glass plates; 
 a gap formed by the pair of glass plates being disposed so as to be opposed to each other with a spacer interposed between the pair of glass plates; and 
 a periphery sealing metal material joining the pair of glass plates at a peripheral portion thereof so as to make the gap airtight, wherein 
 one glass plate of the pair of glass plates has a suction hole penetrating the one glass plate in a front-back direction thereof, 
 air in the gap is sucked so as to depressurize the gap, and the suction hole is sealed by a suction hole sealing metal material having a thermal expansion coefficient different from that of the pair of glass plates, 
 the suction hole sealing metal material keeps an airtight state on the suction hole, 
 the suction hole sealing metal material is formed concentrically with the suction hole in plan view, and 
 the following Expression (1) is satisfied:
     Dw <=( Fc− 0.0361 Pd   2   /Tg   2.2 )/{(−0.0157 Tg+ 0.1945)* Dg}   (1)
 
 
 where Tg is a glass plate thickness (mm), Dw is a protruding portion diameter (mm) of the suction hole sealing metal material, Dg is a protruding portion thickness (mm) of the suction hole sealing metal material, Pd is a spacer pitch (mm), and Fc is long-term permissible stress at a glass edge. 
 
     
     
       2. The glass panel according to  claim 1 , wherein
 the protruding portion diameter Dw of the suction hole sealing metal material is fixed, and is set so as to satisfy the following Expression (2):
     Dg <=( Fc− 0.0361 Pd   2   /Tg   2.2 )/{(−0.0157 Tg+ 0.1945)* Dw}   (2).
 
 
 
     
     
       3. The glass panel according to  claim 1 , wherein
 first tensile stress Fa is set so as to satisfy the following Expression (3):
     Fa =(−0.0157 Tg+ 0.1945)* Dw*Dg<= 5 MPa  (3).
 
 
 
     
     
       4. The glass panel according to  claim 1 , wherein
 first tensile stress Fa is set so as to satisfy the following Expression (4):
     Fa =(−0.0157 Tg+ 0.1945)* Dw*Dg<= 3 MPa  (4).
 
 
 
     
     
       5. The glass panel according to  claim 1 , wherein
 the suction hole sealing metal material is solidified by being dropped from above the suction hole, to keep the airtight state. 
 
     
     
       6. The glass panel according to  claim 1 , wherein
 the spacer is composed of a plurality of pillars interposed in a matrix form at a predetermined pitch so as to keep a predetermined interval between the pair of glass plates, and 
 the pillars are arranged at a narrower pitch in a vicinity of the suction hole than a pitch at another part. 
 
     
     
       7. The glass panel according to  claim 1 , wherein
 the spacer is composed of a plurality of pillars interposed in a matrix form at a predetermined pitch so as to keep a predetermined interval between the pair of glass plates, and 
 at least one other pillar different from the plurality of pillars is provided closer to the suction hole than the plurality of pillars. 
 
     
     
       8. The glass panel according to  claim 1 , wherein
 a width of the periphery sealing metal material as seen in a thickness direction with respect to a plane of the glass panel is 1 to 10 mm. 
 
     
     
       9. The glass panel according to  claim 1 , wherein
 a thickness of at least one of the pair of glass plates is 0.3 to 15 mm. 
 
     
     
       10. The glass panel according to  claim 1 , wherein
 a width of the protruding portion is 2 to 30 mm. 
 
     
     
       11. The glass panel according to a  claim 1 , wherein
 a thickness of the protruding portion is 0.1 to 20 mm. 
 
     
     
       12. The glass panel according to  claim 1 , wherein
 a pitch of the spacer is 5 to 100 mm. 
 
     
     
       13. The glass panel according to  claim 1 , wherein
 a diameter of the suction hole is 2 to 10 mm. 
 
     
     
       14. The glass panel according to  claim 1 , wherein
 at least a lower edge portion of the suction hole is formed in a curved-surface shape or is chamfered.